Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08B—POLYSACCHARIDES; DERIVATIVES THEREOF
  • C08B7/00—Preparation of cellulose esters of both organic and inorganic acids

Definitions

• the speed with which the reaction occurs depends, apart from the temperature, above all upon the water content of the reaction'mixture.
• the reaction sets in only slowly and the cellulose nitrate is not altered.
• the nitric acid radicles are replaced by acetic acid radicles.
• the optimum reaction as regards the reesterification is found to occur when the content of water is about 5%, calculated upon the nitrocellulose. With a content of water exceeding 5%, the violence of the reaction still increases, but less acetate is formed.
• the hydrochloric acid which is formed in a high concentration and in a large excess in comparison with the cellulose ester does not hydrolyze the cellulose ester to a great extent and degrade it say to glucose or the derivatives I thereof; particularly in view of the fact that the glacial acetic acidis entirely consumed for the dissolution of the cellulose nitrate in view of the concentrations of the cellulose nitrate solutions which enter into consideration (above 10 per cent dry content), i. e. that the above reaction occurs within the cellulose micellae while in the form of a solvate.
• reaction mixture after the correctly conducted reaction is complete, consists only of cellulose nitrate-acetate and glacial acetic acid.
• 'I'hionyl chloride completely decomposes under the conditions indicated into volatile constituents, so that only traces of sulfur dioxide and hydrogen chloride are present, substances which, as is known, can easily be eliminated from cellulose'esters. After the nitrate-acetate has been washed free from acid, it is completely stable.
• the thionyl chloride offers special advantages, but the process according to this invention is not limited to the use of this acid chloride. Similar effects are also obtainable with sulfuryl chloride, 100 phosphorus oxychloride, phosphorus trichloride, phosphorus pentachloride, also with phosgene and other substances of similar action, which react with acetic acid and other carboxylic acids while forming their chlorides.
• a special mode of execution of this process is the re-esterification while completely preserving the fiber. It is the same reaction which is performed, the cellulose nitrate is, however, not dissolved, but suspended in a hydrocarbon. Ben 110 zone and the homologues thereof are particularly appropriate, because they penetrate the cellulose micella and, together with the glacial acetic acid or the acetic anhydride added, cause the fibers to swell, whereby the agents can more easily penetrate. Analysis shows that the cellulose nitrate fiber in such mixtures becomes enriched with acetic acid, it is impregnated therewith, and, on addition of acid chlorides, the reaction above indicated occurs in the micella.
• Example 1 100 parts of collodion cotton containing 11.1% of nitrogen and 5% of water (determined by drying the collodion cotton in a desiccator containing P205) are dissolved in 400 parts of glacial acetic acid. 200 parts of'thionyl chloride are added to this solution and the whole :is mixed until a completely homogeneous solution creased, the reaction is completed by heating to 50 C.60 0., whereby currents of hydrogen chlo- 1 ride and sulfur dioxide mixed with nitrous gases escape. The reaction is complete when the evolution of gas'is finished. The clear viscous reaction mixture is poured into water, whereupon the mononitrate-acetate separates in the form of white flakes which are washed until they are free from acid. It contains 5.2% of nitrogen and 41 of acetic acid.
• Example 2 250 grams of commercial acetic anhydride, consisting of 85% of acetic anhydride and 15% of acetic acid, are dissolved in l, liter of benzene. 15 grams of thionyl chloride and 5 grams of sulfuryl chloride are added and 150 grams of collodion cotton having a moisture content of 5%, are introduced into the solution. The
• reaction mixture becomes spontaneously heated within 5 minutes to about 60 C., red'vapors'being simultaneously formed, which are preferably.
• Example 3.20 parts of nitrocellulose containing 11.7% of nitrogen are caused to swell by a.
• nitrocellulose may be transformed into mixed esters by a corresponding treatment with chloro-acetic acid
• acetyl glycolic acid propionic acid, butyric acid and other substituted or, unsubstituted fattyacids.
• fatty-acids include the substituted .and unsubstituted fatty acids.
• the process which comprises dissolving moist nitrocellulose having a nitrogen content of about 16.5 to 12.5 per cent in a concentrated fatty acid and treating the solution with a compound capable of forming the chloride of said fatty acid while developing hydrochloric acid.

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• Chemical & Material Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Biochemistry (AREA)
• Materials Engineering (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Polysaccharides And Polysaccharide Derivatives (AREA)
• Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)

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Country Status (2)

• 1930
  • 1930-12-18 AT AT127817D patent/AT127817B/de active
• 1931
  • 1931-02-18 US US516831A patent/US1980306A/en not_active Expired - Lifetime

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